Abstract: A double-acting power transmission belt having a plurality of elastomeric teeth positioned along both its inner and its outer peripheral surfaces, each such tooth possessing a certain spring rate, and inner and outer jackets, respectively, formed over the teeth and over the land portions between the teeth at each of the inner and outer peripheral surfaces, said inner jacket cooperating with the associated teeth such that the spring rate of each jacketed tooth on the inner one of the peripehral surfaces is from 1.2 times to 3 times the spring rate of a corresponding non-jacketed tooth.

Abstract: A toothed, positive drive, power transmission belt of the type having an endless substantially inextensible tensile member to which are secured belt teeth having a curvilinear cross-section and covered by an outer non-stretch fabric cover. In the body of each tooth is a layer of fabric reinforcement separated from the outer cover fabric of the belt tooth and of the land region between belt teeth by a cushion layer of elastomeric material of varying thickness so that the outer tooth portions are free to flex while the inner portion of the tooth is reinforced against shear. The resulting construction provide belts having substantially longer belt life than conventional belts at relatively high horsepower application.

Abstract: A power transmission belt having a plurality of teeth of elastomeric material positioned along a peripheral surface of said belt, each possessing a predetermined spring rate, and a fabric cover formed over the teeth and over the land portions between the teeth, said fabric cover cooperating with said teeth such that the spring rate of each fabric covered tooth is greater than 1.2 times and less than 3 times the spring rate of such tooth alone.

Abstract: A toothed positive drive power transmission belt of the type having an endless substantially inextensible tensile member to which the belt teeth are secured, which teeth have a curvilinear cross-section and may be covered by an outer protective fabric or the like. In the body of each tooth is a layer of fabric reinforcement separated from the outer surface of the belt teeth by a cushion layer of soft elastomeric material so that the outer surface is free to flex while the inner portion of the tooth is reinforced against shearing.